CD274 and gastric cancer: It has been shown that miR‐16‐5p produced from M1 macrophage‐derived exosomes can boost T cell‐dependent immune response in gastric cancer tissues by targeting PD‐L1 expression,24 implying that exocrine‐derived miR‐16‐5p can contribute to immunotherapy for abnormal PD‐L1 expression in cancer.